Hello, I believe this post is in the correct discussion. I have system that consists of a BLDC motor, and motor controller. (I will post a link below). The arduino is going to act as the I/O board since we are still in the proof-of-concept phase.
I'd like to use a digital potentiometer to 'override' or 'spoof' the potentiometer that limits the current in the motor controller. The goal is to be able to adjust the current limit of the MC with the arduino. This application is torque sensitive, so we will be controlling the motor via current feedback in order to achieve the target torque. Is there a specific Arduino that will be capable of doing this? Just want to make sure the unit is capable before purchasing.
So, where in this motor controller is this current limit potentiometer? I can't see it in that datasheet. To what is it connected? Show us the circuit diagram.
You need all of that before talking about "digital potentiometers".
yes, the pot is a simple voltage divider, so it really feeds back a voltage into the main board.
check the pot, should be 10k which is typical for these type controllers.
but.... why ?
the device takes EITHER, the on-board pot, an external 10k pot or a 0-5vDC signal
any Arduino can output a 0-5V DC signal by means of pwm
you can also buy or make a hybrid, servo/pot by putting a simple servo on a 10k pot. servo control is very simple.
if you need a high quality 0-5VDC output, you can feed a pwm to a filter circuit to get 0-5, or you can use a DAC chip to output your voltage.
if you go the R/C filter route, I assume you would not need a fast or frequent change on the input, therefore you can tune this to minimum ripple, long ramp times. 'long' in electronical terms is seconds BTW http://provideyourown.com/2011/analogwrite-convert-pwm-to-voltage/
as for a servo controlled potentiometer, a simple piece of plastic tubing can be slipped over both shafts to couple them together. then any sort of clamp, rubber bands, duct tape.. to hold the bodies in alignment and all that will turn are the shafts. this is a 30 second project.